This paper presents a distributed shared buffer paradigm based on message passing in distributed computing environment. According to this paradigm, this paper implements a parallel volume rendering algorithm. In order to improve the efficiency of the cache, the parallel algorithm take advantage of octree classification to increase local coherence of the cache in data space. In image space, the parallel algorithm use the Hilbert pixel traversal order to increase the temporal coherence of the cache. The experiments demonstrate good speedup and salability of this approach.